Uptake, Translocation, and Metabolism of Quinclorac in Two Grass Species

Research was conducted to determine the role of uptake, distribution, and metabolism of quinclorac in differential sensitivity of southern crabgrass and Kentucky bluegrass. At 0.5 h, quinclorac uptake was 85% in southern crabgrass and 66% in bluegrass. Uptake and distribution differed between species. By 128 h, Kentucky bluegrass had uniformly distributed quinclorac and exuded 17% into the nutrient solution. Metabolism of quinclorac was limited to less than 3.6% of the applied14C in the two species, at 128 h. Selectivity of quinclorac may be influenced by differences in uptake, distribution, and exudation by the roots but not by metabolism.